The present invention relates to a non-rise faucet assembly and, more particularly to a non-rise faucet having a locator means to resist radial forces, to insure that a predetermined optimum axial sealing force is applied to the associated valve and seat elements of the assembly and to define fluid flow open and closed positions for a faucet valve stem.
In such faucet assemblies, a valve stem is inserted through a bore in a valve body into a chamber. In accord with known practice the valve stem has a disc valve located at a lower end thereof for cooperative engagement with the disc valve seat for regulating the flow of fluid through the body and into a conventional faucet spout upon rotation of the valve stem between fluid flow open and fluid flow closed positions. Such valve stems usually include an upper O-ring placed around the stem for sealing purposes and forces radial to the axis of the valve stem are applied to the O-ring when a handle at the top of the stem is turned. Such radial forces cause O-ring wear, valve stem wear on adjacent surfaces and handle wobble.
In faucets of this type it is essential for long trouble free life that radial forces imposed on the valve stem O-rings and adjacent valve stem surfaces, when the faucet handle is turned, be minimized especially when the faucet stem is constructed of plastic which is more flexible than metal; that a predetermined amount of axial sealing force be applied to urge the valve disc and seat together; and that suitable means be provided for defining the fluid flow open and closed positions of the valve stem at all times even when the faucet handle is removed for service.
One example of the prior art is shown in U.S. Pat. No. 3,788,601, of Jan. 29, 1974, wherein the valve stem is supported against radial forces close to the upper O-ring and wherein a rotational stop means to define fluid flow open and closed positions, is located between the handle and an upward extension of a sleeve. With this design O-ring and valve wear is not minimized. Removal of the handle for services removes the rotational stop means and it is no longer easy to determine where the flow open and closed positions are.
In order to minimize the problem of applying the optimum amount of axial force it is known from aforementioned U.S. Pat. No. 3,788,601 and from U.S. Pat. No. 4,589,629, issued May 20, 1986 to Thomas E. Gaffney et al, to install coil spring biased valve inserts in the valve disc which, move into regulating or sealing registery with fluid flow openings in the valve seat as the valve stem is rotated. When the valve stem is assembled into the body the coil springs are automatically compressed. The valve stem is secured in place by a pin which loosely passes through radially aligned openings in the body and V-shaped openings in the valve. This prior art design does not absorb or minimize the radial force being applied to the valve stem upper O-ring and does not control the amount of axial force as precisely as is desired. The loose fit between the pin, the body and stem results in varying amounts of axial force being applied to the coil springs. The compression rates of the coil springs in faucets of this type are significantly more non-linear than normally expected due to their short axial length necessitated by the small size of the component parts consequently undesirably high variations in valve to valve seat pressure can result. Further, during operation, wear of the pin and the material around its associated opening in the stem, which is usually made of plastic to reduce costs, further increases the tolerances and results in a lessening of the valve to valve seat axial force.
With the above factors in mind it will be appreciated that there exists a need for a simplified faucet design wherein the assembly: will resist and minimize the radial forces applied to the valve stem and its upper O-ring when the faucet handle is turned; will assure that only a predetermined amount of axial sealing force is applied to urge the valve disc and seat together; and will provide rotatable stop means for defining the fluid flow open and closed positions of the faucet at all times even when the handle is removed from service. Further, in order to reduce cost and assembly time, it is desired to accomplish the above needs with a mimimum number of component parts in the faucet assembly. To these ends it is desirable to use a single element of the assembly to automatically absorb and minimize radial forces, to control the optimum amount of axial sealing force and to define the degree of rotation of the stem between fluid flow open and closed positions.